BPK 105 Study Guide - Midterm Guide: Skeletal Muscle
27 Apr 2018
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Module 1 - Objectives - Part 3:
● Define homeostasis and explain why it is important.
homeostasis- the existence and maintenance of a relatively constant environment within the
body despite fluctuations in external/internal environment
normal cell functions depend on the maintenance of the cells’ fluid environment within a narrow
range of conditions, including temperature, volume, and chemical content.
- The organ systems help control the internal environment so that it remains relatively
constant.
- For example, the digestive, respiratory, cardiovascular, and urinary systems function
together so that each cell in the body receives adequate oxygen and nutrients and so
that waste products do not accumulate to a toxic level.
- If the fluid surrounding cells deviates from homeostasis, the cells do not function
normally and may even die.
- Disease disrupts homeostasis and sometimes results in death. Modern medicine
attempts to understand disturbances in homeostasis and works to reestablish a normal
range of values.
● Describe negative feedback and its relationship to homeostasis.
- Most systems of the body are regulated by negative-feedback mechanisms, which
maintain homeostasis.
-Negative
means that any deviation from the set point is made smaller or is resisted.
- Negative feedback does not prevent variation but maintains variation within a normal
range.
- The maintenance of normal body temperature is an example of a negative-feedback
mechanism. Normal body temperature is important because it allows molecules and
enzymes to keep their normal shape so they can function optimally.
- An optimal body temperature prevents molecules from being permanently destroyed.
Thus, normal body temperature is required to ensure that tissue homeostasis is
maintained.
Many negative-feedback mechanisms, such as the one that maintains normal body
temperature, have three components: (1) A receptor monitors the value of a variable, such as
body temperature; (2) a control center, such as part of the brain, establishes the set point
around which the variable is maintained; and (3)an effector, such as the sweat glands, can
change the value of the variable. A changed variable is a stimulus because it initiates a
homeostatic mechanism.
● Normal body temperature depends on the coordination of multiple structures, which are
regulated by the control center, or hypothalamus, in the brain.
Document Summary
The organ systems help control the internal environment so that it remains relatively constant. For example, the digestive, respiratory, cardiovascular, and urinary systems function together so that each cell in the body receives adequate oxygen and nutrients and so that waste products do not accumulate to a toxic level. If the fluid surrounding cells deviates from homeostasis, the cells do not function normally and may even die. Disease disrupts homeostasis and sometimes results in death. Modern medicine attempts to understand disturbances in homeostasis and works to reestablish a normal range of values. Describe negative feedback and its relationship to homeostasis. Most systems of the body are regulated by negative-feedback mechanisms, which. Negative means that any deviation from the set point is made smaller or is resisted. Negative feedback does not prevent variation but maintains variation within a normal maintain homeostasis. range. The maintenance of normal body temperature is an example of a negative-feedback mechanism.
